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diff --git a/Documentation/serial/n_gsm.txt b/Documentation/serial/n_gsm.txt deleted file mode 100644 index 875361bb7cb4..000000000000 --- a/Documentation/serial/n_gsm.txt +++ /dev/null @@ -1,96 +0,0 @@ -n_gsm.c GSM 0710 tty multiplexor HOWTO -=================================================== - -This line discipline implements the GSM 07.10 multiplexing protocol -detailed in the following 3GPP document : -http://www.3gpp.org/ftp/Specs/archive/07_series/07.10/0710-720.zip - -This document give some hints on how to use this driver with GPRS and 3G -modems connected to a physical serial port. - -How to use it -------------- -1- initialize the modem in 0710 mux mode (usually AT+CMUX= command) through -its serial port. Depending on the modem used, you can pass more or less -parameters to this command, -2- switch the serial line to using the n_gsm line discipline by using -TIOCSETD ioctl, -3- configure the mux using GSMIOC_GETCONF / GSMIOC_SETCONF ioctl, - -Major parts of the initialization program : -(a good starting point is util-linux-ng/sys-utils/ldattach.c) -#include <linux/gsmmux.h> -#define N_GSM0710 21 /* GSM 0710 Mux */ -#define DEFAULT_SPEED B115200 -#define SERIAL_PORT /dev/ttyS0 - - int ldisc = N_GSM0710; - struct gsm_config c; - struct termios configuration; - - /* open the serial port connected to the modem */ - fd = open(SERIAL_PORT, O_RDWR | O_NOCTTY | O_NDELAY); - - /* configure the serial port : speed, flow control ... */ - - /* send the AT commands to switch the modem to CMUX mode - and check that it's successful (should return OK) */ - write(fd, "AT+CMUX=0\r", 10); - - /* experience showed that some modems need some time before - being able to answer to the first MUX packet so a delay - may be needed here in some case */ - sleep(3); - - /* use n_gsm line discipline */ - ioctl(fd, TIOCSETD, &ldisc); - - /* get n_gsm configuration */ - ioctl(fd, GSMIOC_GETCONF, &c); - /* we are initiator and need encoding 0 (basic) */ - c.initiator = 1; - c.encapsulation = 0; - /* our modem defaults to a maximum size of 127 bytes */ - c.mru = 127; - c.mtu = 127; - /* set the new configuration */ - ioctl(fd, GSMIOC_SETCONF, &c); - - /* and wait for ever to keep the line discipline enabled */ - daemon(0,0); - pause(); - -4- create the devices corresponding to the "virtual" serial ports (take care, -each modem has its configuration and some DLC have dedicated functions, -for example GPS), starting with minor 1 (DLC0 is reserved for the management -of the mux) - -MAJOR=`cat /proc/devices |grep gsmtty | awk '{print $1}` -for i in `seq 1 4`; do - mknod /dev/ttygsm$i c $MAJOR $i -done - -5- use these devices as plain serial ports. -for example, it's possible : -- and to use gnokii to send / receive SMS on ttygsm1 -- to use ppp to establish a datalink on ttygsm2 - -6- first close all virtual ports before closing the physical port. - -Note that after closing the physical port the modem is still in multiplexing -mode. This may prevent a successful re-opening of the port later. To avoid -this situation either reset the modem if your hardware allows that or send -a disconnect command frame manually before initializing the multiplexing mode -for the second time. The byte sequence for the disconnect command frame is: -0xf9, 0x03, 0xef, 0x03, 0xc3, 0x16, 0xf9. - -Additional Documentation ------------------------- -More practical details on the protocol and how it's supported by industrial -modems can be found in the following documents : -http://www.telit.com/module/infopool/download.php?id=616 -http://www.u-blox.com/images/downloads/Product_Docs/LEON-G100-G200-MuxImplementation_ApplicationNote_%28GSM%20G1-CS-10002%29.pdf -http://www.sierrawireless.com/Support/Downloads/AirPrime/WMP_Series/~/media/Support_Downloads/AirPrime/Application_notes/CMUX_Feature_Application_Note-Rev004.ashx -http://wm.sim.com/sim/News/photo/2010721161442.pdf - -11-03-08 - Eric Bénard - <eric@eukrea.com> |